多向不规则波作用下九桩群桩效应试验研究

Experimental study on piles grouping effect of side by side 9 piles under the action of multi-directional irregular waves

小尺度群桩应用广泛,一直是学者研究的重点,小尺度有别于大尺度桩柱,由于桩柱周围存在漩涡的脱落,使得受力特性复杂。以往的研究过程中,波浪主要采用单向不规则波浪,并且试验模型多以两桩或三桩组成的群桩结构为主,桩数相对较少。多向不规则波与群桩结构的作用特点有别于单向不规则波且研究较少。通过物理模型试验,针对多向不规则波对于9桩桩排群桩结构的作用进行了研究。首先综合考虑KC1/3数和相对桩径的影响,提出以参数KCLD 1/3数来衡量群桩的效应,并分析了正向力与横向力随着参数KCLD 1/3数和相对桩距的变化关系,研究了群桩中不同桩位桩柱波浪力的变化规律和方向分布宽度对于群桩波浪力的影响。研究结果表明,群桩中各桩的正向力随着方向分布标准差的增大而减小,而横向力在相对桩距较大时随着方向分布标准差的增大而增大,同时群桩中不同位置桩上的波浪力具有较大的差异。

The wide application of small scale pile group has always been the focus of scholars'research.Because of the vortex shedding around the piles,small scale piles are different from large scale piles.In most of previous studies,unidirectional irregular waves were used in the experiment.Moreover,pile group is mainly composed of two or three piles,and the number of piles is relatively small.The characteristics of multi-directional irregular wave action on pile group structures are different from those of unidirectional irregular wave action on pile group structures.But there are few researches about this problem.In this research,9piles in side by side arrangement under the action of multi-directional irregular waves are studied by experiment.In this structure,considering the effect of the KC number and relative pile diameter together,the parameter KC LD1/3number is proposed to measure the piles group effect.The relationship between inline force and transverse force with parameter KC LD1/3number and the relative distance is discussed.The change of wave force of piles with different pile positions in pile group is studied.The results show that with the increase of standard deviation of wave directional distribution,the inline force of each pile decreases and transverse force increases.The difference of wave force on the pile in different positions is obvious.